Wed, Sept. 23rd. – First Day of Fall

Equinoxes are opposite on either side of the equator, so the autumnal (fall) equinox in the Northern Hemisphere is the spring (vernal) equinox in the Southern Hemisphere and vice versa.
On the two equinoxes every year the sun shines directly on the equator and the length of day and night is nearly equal – but not exactly.